The present invention relates generally to video signal processing apparatus, and particularly to apparatus adapted for use in association with, or for incorporation into, a video camera used for generating video signals which are to be recorded or broadcast for surveillance purposes.
It is known to use video cameras for recording or transmitting events occurring at a remote location. For example video recordings of high security environments are frequently made as a deterrent or for use as a tool in subsequent detection of intruders. It is significant to note, however, that video recordings do not constitute admissible evidence for legal proceedings unless the time and date information is superimposed on the recording at the time. Apparatus for incorporating such data superimposition is known. Where more sophisticated surveillance pictures are taken, for example from moving vehicles such as aircraft, balloons, marine craft or the like, however, there is no currently available integrated equipment which can provide any more sophisticated data superimposition than merely the time and place.
The present invention is based on the realization that the interpretation of video pictures taken from a moving vehicle can be materially enhanced by the provision of additional data information concerning the vehicle or the camera carried thereby. For example, remote surveillance pictures require for their full interpretation data on a vehicle position which is usually supplied separately from the video recording and which, therefore, necessitates a separate operation in synchronization or matching of the recorded position information with that of the television pictures. This clearly leads to the possibility of errors introduced in effecting such synchronization. In addition, however, information concerning the altitude of the vehicle at the time the pictures are being taken, its speed, heading, altitude and other relevant information may also significantly assist the interpretation of the video recording and, furthermore, materially enhance its value as legal evidence should this be required, or merely as information if this is the purpose of the surveillance. It is believed that marine and airborne reconnaissance operations monitoring vehicle movements for a plurality of reasons such as fisheries protection, information gathering for emergency services, guarding against smuggling of drugs or other contraband items could be materially improved by the direct provision of position information and/or altitude information and/or other motion data generated at the time the video signals are produced regardless of whether they are recorded or transmitted for direct viewing. It is important, however, that the additional data signals carried in association with the video signals should not result in any degradation of the quality of the pictures generated upon display of the signals since clearly this would be a retrograde step. However, there is at present no equipment capable of producing a displayable combined video picture and position or altitude data signal. No prior apparatus is known to the inventors in which picture information generated by a video camera is combined with data information concerning the position, altitude and movement of the camera without permanently obscuring the televised picture.